Subsurface formation tester



Sept. 6, 1960 R. L. MARTIN 2,951,538

SUBSURFACE FORMATION TESTER Filed March 14, 1958 & W/

Ari f FIG.-| FIG.- 2

Richard Loye Murrin Inventor By ZU. Attorney secure a fluid sample.

United States Patent 2,951,538 SUBSURFACE FORMATION TESTER Richard Loye Martin, Tulsa, Okla., assignor, by mesne assignments, to Jersey Production Research Company Filed Mar. 14, 1958, Ser. No. 721,385

7 Claims. (Cl. 166-162) hole samples of formation fluids in a well borehole wherein the pressure about the packing elements is substantially equalized, and wherein flow of fluids from below the formation being tested is not impaired. The formation tester of the present invention essentially comprises two concentrically disposed cylindrical cases movable with respect to one another, each case being characterized by having an exterior and an interior wall.

In the prospecting for oil, it is desirable at times to secure samples of formation fluids up-hole Without the necessity of shutting 013? the flow of fluids from below the formation to be tested. It is also desirable to know the entry location and type of fluids flowing in producing wells. With this information, well completions can be improved-for example, by sealing off undesirable waterand gas-producing intervals which have been located by use of the"tester. Furthermore, the information would be useful in engineering studies of the reservoir. Various types of apparatus and techniques have been suggested for this purpose. However, in most instances, it is necessary to completely shut off the flow of fluids other than from the formation interval to be tested. These techniques which pack ofl and produce only the portion of the formation to be tested require much time and labor. Also, they create large pressure drops across the packers, which results in the by-passing of fluids by way of the formation adjacent the packers. This tends to contaminate the fluid being sampled as well as disturb the normal flow process. The fluid tester of the present invention is an improved apparatus for securing fluid samples from an up-hole formation without the necessity I of stopping the flow of fluids from formations below or above the formation to be tested.

The subsurface fluid tester of the present invention may be readily understood by reference to the drawings illustrating one embodiment of the same. Figure 1 illustrates the device in the closed position being positioned adjacent the formation to be tested and wherein the sample chamber is closed off.- Figure 2 illustrates the fluid tester in the open position wherein fluid from the formation to be tested is flowing from the formation through the sample chamber and co-mingling with upflowing fluid from formations below the formation to be tested. Figure 3 shows a view taken through lines 3-3 of Figure 2.

Referring specifically to Figure l, the fluid tester of the present invention is'shown positioned in a well borehole 1 adjacent formation 2, from which it is desired to The fluid sampler comprises an outer cylindrical case 3, which case is characterized by a cone-shaped head. The head contains ports 20 which permit the flow of fluid therethrough. The outer case 3 is supported by a wire-line assembly which is actuated from the surface and consists of suitable auxiliary means such as hooks, brackets, or their equivalent. The outer case 3 consists of an exterior cylindrical wall 4 and an interior cylindrical wall 5. These respective cylindrical elements-namely, 4 and 5-are rigidly attached to each other by suitable means, as, for example, by means of a head plate 21. Exterior wall 4 contains ports or openings-namely, 13a, 13b, 1'32, and 13 Interior wall or cylinder 5 contains openings or ports 16a, 16b, 16c, 16d, 162, and 16 Cylinder 5 provides a free fluid passageway 22 from below the entire assembly to the cone-head section of the outer case 3. Ports 20 permit free fluid passage from within the cone head to the area above the assembly.

The ports 13a, and 13;) of outer wall 4 are closed off by means of leaf spring and fabric assemblies 12a, 12b, 12c, and 12d which operate in a manner as hereinafter described. The leaf spring and fabric assemblies 12a, 12b, 12c, and 12d may take a form similar to the packers shown in US. Patent No. 2,781,852, issued February 16, 1957. The device of the present invention shown in the drawing schematically as illustrated by Figure 1 also comprises an inner case 6 comprising an interior wall 7 and an exterior Wall 8 positioned between walls 4 and 5 and movable relative thereto. Exterior wall 8 contains ports therein-namely, 14a, 14b, 14c, 14d, Me, and 141. The interior wall of the inner case 6 contains ports 15a, 15b, 15c, 15d, 15c, and 157. This inner case is suspended by a suitable wire-line assembly 11 which is actuated from the surface of the earth. Outer case 3 contains, suspended and attached to the inner wall, a weight assembly 9.

Thus, in the apparatus illustrated in Figure 1, downhole fluid flows upwardly in the hole in the annular space between the device and the borehole wall. .Down-hole fluid also passes upwardly within free passageway 22 into the cone-shaped head and through ports 20 to the area above the apparatus. Since the respective ports in the various cylindrical elements are not in alignment, liquid cannot flow into the top annular chamber 18, the middle annular sampling chamber 17, nor into the lower annular chamber 19. Any fluid flowing from formation 2 comingles with the up-flowing fluid from down-hole.

In operation, tension is applied to wire-line assembly 11, thereby raising the inner case with respect to the outer case. The leaf spring assemblies 12a, 12b, 12c, and 12d have one end attached to the inner case and one end attached to the outer case. Under these conditions, compression is applied to the leaf spring or its equivalent, forcing the leaf to thrust outwardly and moving the fabric or equivalent against the borehole wall as illustrated in Figure 2, thus producing a fluid seal. Under these conditions, down-hole liquid can no longer flow upwardly into and through the annular space between the sampling device and the borehole wall but flows only upwardly through passageway 22 and ports 20. Down-hole liquid also flows through the aligned ports 16d, 15a, and 14d into space or chamber 25, thereby equalizing the fluid pressure below space 25 to the pressure within space 25. In a similar manner, up-flowing down-hole liquid flows through similarly aligned ports into spaces 26, 27, and 28.

It is to be understood that, while the upper packer has been described as having two chambers (namely, 27 and 28) and the lower packer also having two chambers (25 and 26), this packer may comprise a single circumferential packer or may have more than two chambers in the 360-type packer.

Formation fluid flows from the formation 2 into the annular area between the formation and the device as sealed off by an upper circumferential packer 27--28 and a lower circumferential packer 25--26. This fluid then flows through ports 13e and Me and into the annular H is filled with the desired formation fluid to be tested while,

at the same time, permitting down-hole fluid to pass upwardlyin the borehole, thereby not creating a large pres- .sure drop-across the packers and consequently preventing the by-passing of fluids by way of the formation adjacent the packers.

It is to be understood that the ports as shown may contain check valves so as to prevent, for example, fluid from passageway 22 to enter sample chamber 17. After a predetermined time period, tension is maintained on wireiline assembly 11 and released on wire-line assembly 10. The weight 9 attached to outer case 3 will cause outer case 3 to move downwardly with respect to inner case 6,

again placing the respective cases in the relationship as illustrated in Figure 1. Under these conditions, the formation sample is trapped in sample chamber 17; and down-hole fluid can again flow upwardly through passageway 22 as wellas .in the annular space between the sampling device and the borehole wall.

The formation tester of the present invention inessence comprises two concentrically disposed cylindrical .cases axially movable with respect to each other, each case being characterized by having an exterior and an 7 interior, wall, the exterior and interior walls of the respective cases being rigidly attached to each other.

The inner case is further characterized by having the annular space between its exterior and interior walls divided into at least three superimposed annular chambers separated from one another. Ports are provided in the respective -wal-ls so as to permit fluid flow through these areas when the formation to be tested is sealed off, while at the same time down-hole fluids may readily flow upwardly through "the cylindrical passageway, thus preventing undue pressure drop. The formation liquid being tested co-mingles with; the up-flowing down-hole fluid until the sample chamber is filled, at which time the intermediate sample "chamber is closed.

- While the invention has been described with respect to one means of securing relative axial motion of the inner case with repect to the outer case, such as a dual wire-line assembly, it is to be understood that other equivalent means may be used tosecurethis relative motion of the two ,cases comprising in essence the present invention.

comprising an exterior cylindrical wall and a concentrically disposed interior cylindrical wall rigidly attached thereto, said inner case being disposed betweensaid walls of said outer case and being movable axially with respect thereto, said inner case being furthercharacterized by having the annular space between its exterior and interior walls divided intoat least three superimposed chambers, said outer case being characterized by having attached to its outer surface upper and lower expansible packing elements actuated by the relative axial movement of said outer case to said inner case, ports in the respective walls aligned so as to permit the flow of fluid through said superimposed chambers when said packers are expanded and to bar the flow of fluid through said superimposed chambers when said packers are retracted, and means to move the outer case to said .inner case axially with respect to each other.

2. Apparatus as defined by claim 1 wherein a weighted mass isattached to the lower end of said outer case.

3.. Apparatus as defined by claim l whereincne edge of said packing elements is attached'to said outer case and wherein the other edge of said packing'elements is attached to said inner case.

4. Apparatus as defined by claim 3 wherein said ports in said walls are so aligned as to permit the flow of fluid through said walls to the space within said packing elements when expanded.

5., Improved-tester for securing up -holeformation fluid samples. which comprises an outer case comprising-an exterior cylindrical element and a concentrically disposed interior cylindrical element rigidly attached to each other at the top edge thereof by means of a doughnut. head plate, thereby establishing a free passageway within said interior cylindrical element, said interior cylindrical element being further characterized by having its lower edge extendbelow the lower edge of said exterior cylindrical element, an inner case comprising an exterior cylindrical element and a concentrically disposed interior cylindrical element rigidly attached thereto, said inner case beingdis- ..posed between said elements of said outer case and being movable axially with respect thereto, said inner case being further characterized by having the annular space between its exterior and interior elements divided into at .1east three superimposed chambers, said outer case beingcharacter- ,are retracted, and means to move the outer case to said inner case axially with respect to each other.

6. Apparatus as defined by claim 5 wherein one edge-of said packing elements is attached to said outer caseand whereinthe other edge of said packing elements isattached to said inner case. 7

7. Apparatus as defined by claim 5 wherein said ports in said elements are so aligned as to permit the-.fiowof fluid through said elements to the space within said packing elements when expanded.

References Cited in the file of this patent UNITED STATES PATENTS 2,156,709 Taylor May 2, 1939 2,210,245 Kimmel Aug. 6, 1940 2,563,284 Seay Aug. 7, 1951 2,711,220 Simmons June. 21,1955 

